fix: salvage truncated worker envelopes and log worker lifecycle

Models occasionally drop the closing tag of the result envelope while
the JSON itself is complete; the strict parser rejected these and one
repair attempt could not always recover, cascading into worker_error
and dropping valid attachments. The parser now falls back to
brace-balanced salvage when the closing tag is missing, and worker
lifecycle events (start, resume, invalid envelope, repair, settle,
worker_error) are logged.

test/assistant-manager.test.ts

@@ -502,6 +502,39 @@ test("envelope parsers accept valid tails and reject invalid ones", () => {
   assert.equal(parseAssistantActions(`x\n<GORI_ASSISTANT_ACTION_V2>{"reply":"hi","actions":[{"type":"send_image"}]}</GORI_ASSISTANT_ACTION_V2>`), undefined);
 });
 
+test("envelope parsers salvage envelopes missing only the closing tag", () => {
+  // Complete JSON truncated at the closing tag is accepted, attachments included.
+  assert.deepEqual(
+    parseWorkerResult(`worker reply\n<GORI_WORKER_RESULT_V2>{"status":"PENDING","summary":"s","attachments":[{"path":".gori-outbox/a.png"}]}`),
+    { status: "PENDING", summary: "s", question: undefined, workspaceDirty: undefined, attachments: [{ path: ".gori-outbox/a.png", mimeType: undefined }] }
+  );
+  // Braces and escapes inside strings do not confuse the balancing.
+  assert.deepEqual(
+    parseWorkerResult(`r\n<GORI_WORKER_RESULT_V2>{"status":"PENDING","summary":"use {a} and \\"}\\" end"}`),
+    { status: "PENDING", summary: "use {a} and \"}\" end", question: undefined, workspaceDirty: undefined, attachments: undefined }
+  );
+  // Trailing whitespace after the balanced JSON is fine, trailing content is not.
+  assert.deepEqual(
+    parseWorkerResult(`r\n<GORI_WORKER_RESULT_V2>{"status":"PENDING","summary":"s"}\n`),
+    { status: "PENDING", summary: "s", question: undefined, workspaceDirty: undefined, attachments: undefined }
+  );
+  // JSON cut off mid-object stays invalid.
+  assert.equal(parseWorkerResult(`r\n<GORI_WORKER_RESULT_V2>{"status":"PENDING","summary":"cut off`), undefined);
+  // Balanced JSON with trailing content (e.g. a closing tag plus more text) stays invalid.
+  assert.equal(parseWorkerResult(`r\n<GORI_WORKER_RESULT_V2>{"status":"PENDING","summary":"s"}</GORI_WORKER_RESULT_V2> extra`), undefined);
+  assert.equal(parseWorkerResult(`r\n<GORI_WORKER_RESULT_V2>{"status":"PENDING","summary":"s"} trailing`), undefined);
+  // Salvage never accepts an invalid payload even when the JSON balances.
+  assert.equal(parseWorkerResult(`r\n<GORI_WORKER_RESULT_V2>{"status":"SUCCESS","summary":"s"}`), undefined);
+
+  assert.deepEqual(
+    parseAssistantActions(`ok\n<GORI_ASSISTANT_ACTION_V2>{"reply":"ok","actions":[]}`),
+    { reply: "ok", actions: [] }
+  );
+  assert.equal(parseAssistantActions(`ok\n<GORI_ASSISTANT_ACTION_V2>{"reply":"ok","actions":[{"type":"stop"}`), undefined);
+  assert.equal(parseAssistantActions(`ok\n<GORI_ASSISTANT_ACTION_V2>{"reply":"ok","actions":[]}</GORI_ASSISTANT_ACTION_V2> more`), undefined);
+  assert.equal(parseAssistantActions(`ok\n<GORI_ASSISTANT_ACTION_V2>{"reply":"ok","actions":[]} trailing`), undefined);
+});
+
 test("an owner's own pending proposal blocks their start_next with an actionable correction", async () => {
   const harness = await createHarness();
   try {
@@ -689,6 +722,57 @@ test("image attachments degrade to a text note when the agent has no image capab
   }
 });
 
+test("a worker envelope truncated at the closing tag is salvaged without a repair round", async () => {
+  const harness = await createHarness();
+  try {
+    await harness.manager.prompt(request("create proposal: truncattach"));
+    const proposal = harness.proposals.list()[0]!;
+    await harness.manager.prompt(request("confirm"));
+    await waitFor(() => harness.proposals.get(proposal.id)!.status === "pending");
+
+    const pending = harness.proposals.get(proposal.id)!.pending!;
+    assert.equal(pending.summary, "made a pic");
+    assert.equal(pending.attachments?.length, 1);
+    assert.ok(pending.attachments![0]!.path.endsWith(path.join(".gori-outbox", "shot.png")));
+
+    const repairs = readLog(harness.logFile).filter((entry) => entry.method === "session/prompt"
+      && entry.text?.startsWith("Your previous response did not end with a valid GORI_WORKER_RESULT_V2"));
+    assert.equal(repairs.length, 0);
+  } finally {
+    await closeHarness(harness);
+  }
+});
+
+test("a worker envelope with unbalanced JSON still goes through exactly one repair round", async () => {
+  const harness = await createHarness();
+  try {
+    await harness.manager.prompt(request("create proposal: truncbad"));
+    const proposal = harness.proposals.list()[0]!;
+    await harness.manager.prompt(request("confirm"));
+    await waitFor(() => harness.proposals.get(proposal.id)!.status === "pending");
+
+    assert.equal(harness.proposals.get(proposal.id)!.pending?.summary, "repaired");
+    const repairs = readLog(harness.logFile).filter((entry) => entry.method === "session/prompt"
+      && entry.text?.startsWith("Your previous response did not end with a valid GORI_WORKER_RESULT_V2"));
+    assert.equal(repairs.length, 1);
+  } finally {
+    await closeHarness(harness);
+  }
+});
+
+test("an assistant envelope truncated at the closing tag is salvaged without a repair round", async () => {
+  const harness = await createHarness();
+  try {
+    const reply = await harness.manager.prompt(request("truncated assistant"));
+    assert.equal(reply.text, "ok");
+    const repairs = readLog(harness.logFile).filter((entry) => entry.method === "session/prompt"
+      && entry.text?.startsWith("Your previous response did not end with a valid GORI_ASSISTANT_ACTION_V2"));
+    assert.equal(repairs.length, 0);
+  } finally {
+    await closeHarness(harness);
+  }
+});
+
 test("worker attachments are validated against the workspace and ride along with the owner event", async () => {
   const harness = await createHarness();
   try {